Electrical overstress recording and/or harvesting

ABSTRACT

Aspects of this disclosure relate to detecting and recording information associated with electrical overstress (EOS) events, such as electrostatic discharge (ESD) events. For example, in one embodiment, an apparatus includes an electrical overstress protection device, a detection circuit configured to detect an occurrence of the EOS event, and a memory configured to store information indicative of the EOS event.

BACKGROUND

1. Technical Field

The disclosed technology relates to electronic systems, and, moreparticularly, to taking action responsive to and/or in anticipation ofan electrical overstress event.

2. Description of the Related Technology

Certain electronic systems can be exposed to electrical overstressevents. Such events can cause damage, such as thermal damage, as aresult of an electronic device experiencing a current and/or a voltagethat is beyond the specified limits of the electronic device. Forexample, an electronic device can experience a transient signal event,or an electrical signal of short duration having rapidly changingvoltage and high power. Transient signal events can include, forexample, electrostatic discharge (ESD) events arising from the abruptrelease of charge from an object or person to an electronic system, or avoltage/current spike from the electronic device's power source.

Electrical overstress events, such as transient signal events, candamage integrated circuits (ICs) due to overvoltage conditions and highlevels of power dissipation in relatively small areas of the ICs, forexample. High power dissipation can increase IC temperature, and canlead to numerous problems, such as gate oxide punch-through, junctiondamage, metal damage, surface charge accumulation, the like, or anycombination thereof.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

One aspect of this disclosure is an apparatus that includes anelectrical overstress protection device, a detection circuitelectrically coupled to the electrical overstress protection device, anda memory. The detection circuit is configured to detect an occurrence ofan electrical overstress event. The memory is configured to storeinformation indicative of the electrical overstress event detected bythe detection circuit.

Another aspect of this disclosure is an apparatus that includes anelectrical overstress protection device, a detection circuitelectrically connected to the electrical overstress protection device,and a reporting circuit in communication with the detection circuit. Thedetection circuit is configured to detect an occurrence of an electricaloverstress event. The reporting circuit is configured to provideinformation indicative of the electrical overstress event detected bythe detection circuit.

Another aspect of this disclosure is an electronically-implementedmethod of recording information associated with an electrical overstressevent. The method includes detecting, using detection circuitryelectrically connected to an electrical overstress protection device, anoccurrence of an electrical overstress event. The method also includesrecording information associated with the occurrence of the electricaloverstress event to a memory.

Another aspect of this disclosure is an apparatus that includes anelectrical overstress steering device and a storage element configuredto store charge associated with an electrical overstress event, in whichthe electrical overstress steering device is configured to provideenergy associated with the electrical overstress event to the storageelement.

The electrical overstress device can be disposed between a contact, suchas a pin, of an electronic device and the storage element. An electricaloverstress protection device can be electrically connected to thecontact to provide electrical overstress protection. The storage elementcan include, for example, a capacitor. The electrical overstresssteering device can be electrostatic discharge steering device andelectrical overstress event can be an electrostatic discharge event.

Another aspect of this disclosure is an apparatus that includes aproximity sensor, an electrical overstress configuration circuit, and anelectrical overstress protection circuit. Responsive receiving anindication of proximity from the proximity sensor, the electricaloverstress configuration circuit can configure the electrical overstressprotection circuit. For example, the electrical overstress configurationcircuit can pre-trigger and/or prime the electrical overstressprotection circuit.

Another aspect of this disclosure is an apparatus that includes aproximity sensor, a storage element, a storage element configurationcircuit, and an electrical overstress steering device. The storageelement can store charge associated with an electrical overstress event,in which the electrical overstress steering device is configured toprovide energy associated with the electrical overstress event to thestorage element. Responsive receiving an indication of proximity fromthe proximity sensor, the storage element configuration circuit canconfigure the storage element.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the inventions have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment of the invention.Thus, the invention may be embodied or carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other advantages as may be taughtor suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic block diagram of an electronic system thatincludes electrical overstress detection circuitry, energy harvestingcircuitry, and a proximity sensor according to an embodiment.

FIG. 1B is a schematic diagram of an illustrative electronic device thatincludes electrical overstress detection circuitry according to anembodiment.

FIGS. 2A to 2D illustrate example electrical overstress protectiondevices that can be implemented in one or more embodiments.

FIG. 3 is a schematic diagram of a portion of an illustrative electronicdevice configured to detect an electrical overstress event at a pin ofthe electronic device according to an embodiment.

FIG. 4 is a schematic diagram of a portion of an illustrative electronicdevice configured to detect electrical overstress events across astorage element according to an embodiment.

FIG. 5 is a schematic diagram that includes a detection circuit and anelectrical overstress protection device according to an embodiment.

FIG. 6 is a schematic diagram that includes a detection circuit and anelectrical overstress protection device according to another embodiment.

FIG. 7 is a schematic diagram that includes a detection circuit and anelectrical overstress protection device according to another embodiment.

FIG. 8 is a schematic diagram that includes a detection circuit and anelectrical overstress protection device according to another embodiment.

FIG. 9 is a schematic diagram of an illustrative circuit that isconfigured to detect and store information associated with electricaloverstress events according to an embodiment.

FIG. 10 is a schematic diagram of a portion of an electronic device withan electrical overstress event detection circuit according to anembodiment.

FIG. 11 is a diagram of stacked dies including a die that includesfunctional safety circuitry according to an embodiment.

FIG. 12 is a diagram of a system in a package that includes functionalsafety circuitry according to an embodiment.

FIG. 13 is a diagram of a system that includes functional safetycircuitry according to an embodiment.

FIG. 14 is a schematic diagram of an illustrative electronic device thatis configured to store charge associated with an electrical overstressevent according to an embodiment.

FIG. 15 is a schematic diagram of an illustrative electronic device thatis configured to store charge associated with an electrical overstressevent and to detect an occurrence of the electrical overstress eventaccording to an embodiment.

FIG. 16 is a schematic diagram of a portion of an illustrativeelectronic device configured to store charge associated with anelectrical overstress event according to an embodiment.

FIG. 17 is a schematic diagram of a portion of an illustrativeelectronic device configured to store charge associated with anelectrical overstress event in a bank of storage elements according toan embodiment.

FIG. 18 is a schematic diagram of a circuit configured to store chargeassociated with an electrical overstress event according to anembodiment.

FIG. 19 is a schematic diagram of a circuit configured to store chargeassociated with an electrical overstress event according to anotherembodiment.

FIG. 20 is a schematic diagram of a circuit configured to store chargeassociated with an electrical overstress event according to anotherembodiment.

FIG. 21 is a schematic diagram of a circuit configured to store chargeassociated with an electrical overstress event according to anotherembodiment.

FIG. 22 is a schematic diagram of a circuit configured to store chargeassociated with an electrical overstress event according to anotherembodiment.

FIG. 23A is a plan view of an example layout of an electrical overstressprotection device according to an embodiment.

FIG. 23B is a plan view of another example layout of an electricaloverstress protection device according to an embodiment.

FIG. 23C is a plan view of another example layout of an electricaloverstress protection device according to an embodiment.

FIG. 24 illustrates another electrical overstress protection devicewhere the current surge is conducted vertically through to the layerbelow according to an embodiment.

FIG. 25 illustrates an example of a vertically integrated system withscaled up structures capable of harnessing an electrical overstressevent for storing charge according to an embodiment.

FIG. 26 is a schematic diagram of a vertically integrated system thatincludes electrical overstress protection and energy harvestingcircuitry according to an embodiment.

FIG. 27 is a schematic diagram of a vertically integrated system thatincludes electrical overstress protection and energy harvestingcircuitry on a single chip according to an embodiment.

FIG. 28 illustrates a die with electrical overstress protection devices,storage elements, and processing circuitry according to an embodiment.

FIG. 29 illustrates a die with electrical overstress protection devices,storage elements, and processing circuitry according to anotherembodiment.

FIGS. 30A and 30B illustrate an embodiment of a mobile device thatincludes an external casing having conduits embedded within the externalcasing according to an embodiment.

FIG. 30C illustrates an embodiment of a wearable device that includes anexternal casing having conduits embedded within the external casingaccording to an embodiment.

FIG. 31 illustrates examples of conductive structures in an opening of apackage that can provide electrical connections to ESD protectiondevices according to various embodiments.

FIG. 32 illustrates a system that includes a rotating shaft and a chargeharvesting system according to an embodiment.

FIG. 33A illustrates a rotating shaft having a layer of material forenhancing electrostatic charge and/or field generated by a rotatingshaft and a charge harvesting system according to an embodiment. FIG.33B illustrates that the layer of material incorporated on a rotatingshaft can have a non-uniform width in certain embodiments. FIG. 33Cillustrates a selected surface topography of the layer of material ofthe energy harvesting system according to an embodiment. FIG. 33Dillustrates a surface finish on the layer of material of the energyharvesting system according to an embodiment.

FIG. 33E is a block diagram of another context in which energyharvesting can be implemented according to an embodiment.

FIG. 34 is a schematic block diagram of an illustrative electronicdevice that can condition or initiate electrical overstress protectionin response to proximity sensing information according to an embodiment.

FIG. 35 is a schematic block diagram of an illustrative electronicdevice that can configure a storage element arranged to store energyassociated with an electrical overstress event using proximity sensinginformation according to an embodiment.

FIG. 36 illustrates an example electronic device with energy harvestingand storage and/or EOS event detection circuitry according to anembodiment.

FIG. 37 illustrates an example electronic device with energy harvestingand storage and/or EOS event detection circuitry according to anembodiment.

FIG. 38 illustrates an example electronic device with energy harvestingand storage and/or EOS event detection circuitry according to anembodiment.

FIG. 39 illustrates an example electronic device with energy harvestingand storage and/or EOS event detection circuitry according to anembodiment.

FIG. 40 illustrates an example electronic device with energy harvestingand storage and/or EOS event detection circuitry according to anembodiment.

FIG. 41 illustrates an example electronic device with energy harvestingand storage and/or EOS event detection circuitry according to anembodiment.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The following detailed description of certain embodiments presentsvarious descriptions of specific embodiments. However, the innovationsdescribed herein can be embodied in a multitude of different ways, forexample, as defined and covered by the claims. In this description,reference is made to the drawings where like reference numerals canindicate identical or functionally similar elements. It will beunderstood that elements illustrated in the figures are not necessarilydrawn to scale. Moreover, it will be understood that certain embodimentscan include more elements than illustrated in a drawings and/or a subsetof the illustrated elements. Further, some embodiments can incorporateany suitable combination of features from two or more drawings. Theheadings provided herein are for convenience only and do not necessarilyaffect the scope or meaning of the claims.

Structures for protection against electrostatic discharge (ESD) or otherelectrical overstress events on an integrated circuit, such as a siliconchip, can occupy about 15% to about 20% of total integrated circuit areain certain applications. Over the last 40 years, structures used for theconduction, discharge/dissipation of static charge/ESD events haveimproved such that integrated circuits are able to withstand highercurrents, higher voltages, transient events, etc. Such ESD protectionstructures can divert a signal surge to ground. While this disclosuremay discuss ESD protection circuits and ESD events for illustrativepurposes, it will be understood that any of the principles andadvantages discussed herein can be applied to any other electricaloverstress (EOS) condition. EOS events can encompass a variety of eventsincluding transient signal events lasting about 1 nanosecond or less,transient signal events lasting hundreds of nanoseconds, transientsignal events lasting on the order of 1 microsecond, and direct current(DC) overstresses.

In this disclosure, detecting/recording/reporting electrical overstressevents, harvesting energy associated with electrical overstress events,and configuring electrical overstress protection circuits responsive toan indication that an electrical overstress is likely to occur aredisclosed. The principles and advantages of any one of these conceptscan be applied in connection with one or more of the other concepts.

Typical ESD protection circuits can protect internal circuits frompotentially damaging ESD events without storing or otherwise reportingthat an ESD event has occurred. As such, information associated with theoccurrence of an ESD event is unavailable to an electronic system. Incertain applications, there is a need for reliable circuit operation.For instance, when electronics in a car or other vehicle fail, suchfailures can threaten safety of a driver and/or a passenger. As anotherexample, it can be desirable for electronics in healthcare applications,such as heart rate monitoring applications, to reliably detect a changein a physiological parameter so that proper action can be takenresponsive to detecting such a change. When circuits in such healthcareapplications fail, health can be adversely impacted. In applicationswhere there is a need for reliable circuit operation, unknown potentialdamage to critical circuits can be problematic.

Aspects of this disclosure relate to detecting and recording electricaloverstress events. An electrical overstress event can be detected andinformation indicative of the electrical overstress event can be storedto memory and/or be reported external to an electronic device. Detectioncircuitry can detect an electrical overstress event and, in someinstances, an intensity of the electrical overstress event. Physicalmemory can store information indicative of an intensity of an overstressevent and/or a number of occurrences of electrical overstress events.The detection circuitry and the memory can be part of the sameintegrated circuit (e.g., on the same die and/or within the samepackage) as the electrical overstress protection circuitry. In anembodiment, the detection circuit and the memory can be implemented by acombined detection and memory circuit.

The information associated with the electrical overstress event storedin the memory can be useful for functional safety purposes. Forinstance, this information can serve as indication of wear or lifespanof the device, indicate that an electronic device is potentiallydamaged, that data provided by an electronic device is potentiallycorrupt, that a measurement provided by an electronic device ispotentially inaccurate, the like, or any combination thereof. Theinformation associated with an electrical overstress event can bereported to provide information about the functional safety ofelectrical overstress protection circuitry and/or of internal circuit(s)protected by the electrical overstress protection circuitry. Theelectronic overstress detection and reporting circuitry can provide anearly indication of adverse conditions, analogous to a canary in a coalmine. In harsh environments, the electronic overstress detection andreporting circuitry can provide indicators of a lifespan of anelectronic device and/or an electronic system. Tracking the lifespan ofan electronic device by recording and reporting electrical overstressevents can lead to better reliability of critical circuit and/orpredictability of time for replacement. This can be advantageous in avariety of applications, such as in preventing failures in vehicles thatcan threaten safety and/or in healthcare applications.

For instance, a custom semiconductor die operating in an electronicdevice can record information indicative of an occurrence of anelectrical overstress (e.g., overvoltage and/or ESD) event in memory ofthe semiconductor die. The occurrence of the overstress event mayindicate that there is a fault within the electronic device. Theoccurrence of the electrical overstress event may indicate that externalprotection circuitry, i.e., circuitry connected to the customsemiconductor die, such as separate protection circuitry on another chipor on a board, is faulty such that a semiconductor die experiencessurges and/or current spikes outside of a specification for circuitry tobe protected, which can be on the custom semiconductor die or outside ofthe custom semiconductor die. As an example, a solder joint for theexternal protection circuitry can degrade and thus provide less thandesirable protection from an overvoltage event. The semiconductor diecan provide the information indicative of the occurrence of theelectrical overstress event external to the semiconductor die and/orexternal to an electronic device that includes the semiconductor die.This can serve as a diagnostic to inform an electronic system thatelectrical overstress protection circuitry is no longer functioning at adesired level.

A specialized semiconductor die can be devoted to handling electricaloverstress, including detection and recording information indicative ofoverstress events in a memory of the semiconductor die. The specializedsemiconductor die can also serve to harvest energy associated with EOSevents and/or to provide EOS protection. In certain implementations,recording functions can be implemented on a different semiconductor diethan EOS protection functions.

In some instances, an integrated circuit may have a limited/defined lifespan. This can result from, for example, being in a harsh electricalenvironment. The electrical overstress detection and reporting circuitrycan provide information about an intensity of an electrical overstressevent and/or a number of occurrences of electrical overstress events asflags to an electronic system. After a defined number of electricaloverstress events have been detected, the electronic system can providea flag that an electronic device has a reduced lifespan. Such a flag canindicate that the electronic device is due for replacement relativelysoon or within a defined period of time. Tracking the lifespan of adevice can lead to better reliability of critical circuits and/or abetter prediction of time for replacement.

Information indicative of electrical overstress events can be providedexternally to an electronic device that experiences the electricaloverstress events or to separate monitoring circuitry or devices. Forinstance, wireless and/or inductive circuits can provide signal remoteto the electronic device to provide a warning and/or a status of theheath of the electronic device or an electronic system that includes theelectronic device. Such warnings can provide indicators of the life spanof the system and/or general system health. This can enable planning fora new/replacement electronic device to be included in the electronicsystem. These principles and advantages can be applied to a variety ofelectronic systems, such as electronic systems in cars and/or othervehicles and/or in healthcare applications.

Aspects of this disclosure relate to storing charge associated withelectrical overstress events, such as ESD events. ESD protectioncircuits, which can protect internal circuits from overvoltage events,typically divert charge to ground. A significant amount of energy can beassociated with an ESD event. Instead of dissipating all chargeassociated with ESD events, a significant amount of the charge can bestored in a storage element, such as capacitor(s), and the stored chargecan then be used by the electronic system. For example, such storageelements can be employed to supply power for events such as periodicwireless transmissions, to smooth out power delivery, to supplement orreplace battery power, or any combination thereof. To facilitate storingchange associated with ESD events, ESD protection structures can bescaled up (e.g., configured to carry more current and/or conduct/funnelmore energy). While ESD events may be described in connection withharvesting change, it will be understood that charge can be harvestedfrom any other EOS event in accordance with the principles andadvantages discussed herein.

At a system level, electrical overstress protection circuits can besegregated (e.g., chips or layers in a package can be devoted to EOSevent handling) and/or scaled up. Such electrical overstress protectioncircuits can be configured such that they provide system levelelectrical overstress protection; energy associated with electricaloverstress events can be routed to a storage element; and/or EOS eventscan be detected and recorded. Charge stored by the storage element canbe subsequently used within the system. In some instances, system levelelectrical overstress protection circuits and storage elements thatstore harvested energy from electrical overstress events can beimplemented in industrial applications or other instances where currentsurges or other electrical overstress events are expected. In suchinstances, an electronic system can be arranged to harvest charge frommoving/rotating mechanisms prone to generation of static charge, forexample.

In situations where an electronic device operates intermittently, thecharge associated with an electrical overstress event that is stored bya storage element can be used to carry out another specific/definedfunction. For example, responsive to an ESD event, the harvested chargecan be used to activate circuitry and record, for example, that an ESDevent has occurred. Similarly, in situations where temporary/transientcharge harvested from, for example, an ESD event is sufficient to carryout a task, an electronic device can carry out the task using theharvested charge. In certain applications, responsive to an ESD event,harvested charge can be used to activate circuitry and recordinformation associated with the ESD event, for example, in accordancewith the principles and advantages discussed herein associated withdetecting an EOS event.

At a micro level, if 15% to 20% of die area that is already consumed byESD protection circuitry is used to reduce power consumption of asemiconductor chip and there are a number of such chips within anelectronic system, then over power consumption and system efficiency canbe significantly improved by storing and subsequently using chargeassociated with an ESD event. For example, even a relatively smallreduction in power consumption in a system with a relatively largenumber of chips (e.g., 500 chips) can add up over a long period of time(e.g., 5 to 10 years). The charge stored from harvesting can be employedto prolong battery life for the system, particularly for remotemonitoring systems, to reduce power consumption from external sources,to power circuitry for recording EOS events, etc.

Harvesting charge associated with electrical overstress events can beimplemented in a number of different contexts. For example, harvestingchange associated with ESD or other electrical overstress events can beimplemented in certain industrial applications where a system could beconstructed specifically to generate and store charge from moving and/orrotating parts.

A storage element that receives and stores energy associated with anelectrical overstress event can include capacitor(s) and/or a battery.For instance, the storage element can include a super capacitor and/orthin film lithium ion battery. In these storage elements, leakage can bea concern, particularly when charge is intermittently harvested.

The storage element can be constructed to enhance (e.g., optimize) theflow of current into the storage areas. The storage element can bearranged such that current associated with an electrical overstressevent can only flow in one direction during the storing phase, i.e.,once the current flows into the storage area it does not flow back outthe same path/conduit/channel. A level of charge stored by the storageelement can be detected. The storage element can provide a signalindicative of how much charge is stored by the storage element. Thissignal can be used, for example, to indicate that the storage elementhas sufficient charge to provide to an electronic system. Informationabout the amount of charge stored by the storage element can be providedto other circuitry, such as remote circuitry external to a die thatincludes the storage element and/or remote to an electronic system thatincludes the storage element. The storage element can be activated orotherwise configured to be responsive to an indication that an EOS eventis likely to occur. Different banks of storage components, such ascapacitors, can be switched on and/or off as they charge. When a bank ofstorage components stores approximately a maximum amount of charge,charge associated with an EOS event can be routed to a different bank ofstorage elements.

In some applications, an electronic system can be powered by acombination of energy harvested from an electrical overstress event anda primary power source. When harvested energy is available, it can usedto power the electronic system. When the stored energy is depleted, thesystem can switch to using the primary power source until harvestedenergy becomes available. When using an energy harvesting, voltage on acapacitor in the storage element can be monitored. Responsive todetecting that sufficient charge is stored on the capacitor, aninterrupt can be provided to inform the system sufficient energy isavailable to transmit a signal from the electronic system.

Aspects of this disclosure relate to detecting proximity of anelectrical field and configuring circuitry for EOS protection and/orharvesting energy from an EOS event responsive to detecting proximity.For instance, an EOS device can be conditioned, e.g., primed to triggerin response to an indication that an EOS event is likely to occur as aresult of sensing proximity. Such features can be implemented inapplications in which EOS events occur for very short durations, e.g.,on the order of nanoseconds or a shorter duration of time, such that thecharge from such rapid events may not be captured without predictivetriggering. As another example, clamping of an ESD protection circuitcan be actively controlled responsive to detecting proximity. In onemore example, a storage element can be activated to capture chargeassociated with an EOS event responsive to detecting proximity.

FIG. 1A is a schematic block diagram of an electronic system 1 thatincludes electrical overstress detection circuitry, energy harvestingcircuitry, and a proximity sensor according to an embodiment. Theelectronic system 1 can be a system on a chip as illustrated. Theelectronic system 1 is an example of a system that can implementfeatures of EOS event detection, harvesting energy associated with EOSevents, and configuring EOS devices and/or storage elements forharvested energy based on proximity sensing information. The electronicsystem 1 of FIG. 1A includes EOS protection devices 2, antennas 3 and 4,an EOS event detection circuit 16, a reporting circuit 18, a storageelement 144, a data storage and processing circuit 5, a communicationbus transmitter circuit 6, an antenna transmission circuit 7, and aproximity sensor 342. Some other embodiments can include more elementsthan illustrated and/or a subset of the illustrated elements.

EOS protection devices 2 can provide EOS protection for internalcircuits of the electronic system. The EOS protection devices canimplement one or more EOS sense devices, such as the EOS sense device 14of FIG. 1B or the ESD sense device 34 of FIG. 3, and one or more EOSsteering devices, such as the ESD steering device 32 of FIG. 3 or theEOS steering device 142 of FIG. 14 or FIG. 15.

The EOS event detection circuit 16 can detect an occurrence of an EOSevent. In some embodiments, the EOS detection circuit 16 can detect anintensity and/or a duration of an EOS event. The EOS event detectioncircuit 16 can provide information associated with an EOS event to thedata storage and processing circuit 5 to be recorded. The EOS eventdetection circuit 16 can provide information associated with an EOSevent to the antenna transmission circuit, which can transmit suchinformation via the antenna 4. The EOS event information canalternatively or additionally provide information associated with an EOSevent to the communication bus transmitter 6 for transmission by way ofa communications bus. In an embodiment, the communication bustransmitter 6 can be part of a transceiver.

The storage element 144 can storage energy associated with an EOS event.The storage element 144 can include one or more capacitors, for example.Charge stored by the storage element 144 can power other circuits of theelectronic system 1 and/or be provided external to the electronic system1.

The proximity sensor 342 can sense proximity of an object and provideproximity information to the EOS event detection circuit 16 and/or thedata stage and processing circuit 5. Using proximity information, thesecircuits can configure one or more of the EOS protection devices 2and/or the storage element.

Detecting Electrical Overstress Events

As discussed above, aspects of this disclosure relate to detectingelectrical overstress events, such as ESD events. Information associatedwith EOS events can be recorded and/or reported. This can provideinformation about the functional safety of a circuit, a die, anintegrated circuit system, or the like. Such information can beindicative of an intensity of an EOS event, a duration of an EOS event,and/or of a number of occurrences of EOS events detected. In someembodiments, information associated with EOS events can be indicative ofa pulse width of an EOS event, as an EOS event can have an arbitrarywaveform. Such information can be recorded for each EOS pulse and/ormultiple records can be captured per pulse. Illustrative embodimentsrelated to EOS event detection will now be discussed.

FIG. 1B is a schematic diagram of an illustrative electronic device 8that includes electrical overstress detection circuitry according to anembodiment. The electronic device 8 can be implemented in a variety ofapplications. As some examples, the electronic device 8 and/or otherelectronic devices discussed herein can be included in an automotiveelectronics system, an avionics electronics system, a healthcaremonitoring electronics system, or the like. As illustrated, theelectronic device 8 includes an input contact 10, an EOS protectiondevice 11, an EOS isolation device 12, an internal circuit 13, an EOSsense device 14, a resistive element 15, a detection circuit 16, amemory 17, a reporting circuit 18, and an output contact 19. Theillustrated elements of the electronic device 8 can be included within asingle package. The electronic device 8 can include more elements thanillustrated and/or a subset of the illustrated elements. The electronicdevice 10 can be a die, for example. As such, in some instances, theillustrated elements of the electronic device 8 can be embodied on asingle die.

The electronic device 8 is configured to receive an input signal at theinput contact 10, which can be an input pin as illustrated. The EOSprotection device 11 is configured to provide protection from electricaloverstress events. The illustrated EOS protection device 11 isconfigured to protect the circuitry electrically connected to the inputcontact 10 by diverting current associated with an EOS event to groundwhen a signal on the input contact 10 exceeds an EOS capability of thedevices being protected, e.g., voltage breakdown. The EOS protectiondevice 11 can protect the internal circuit 13 and the resistive element15 from electrical overstress events. The EOS protection device 11 canalso protect any other circuitry electrically connected to the inputcontact 10. The EOS isolation device 12 is disposed between the internalcircuit 13 and the pin in FIG. 1B. The EOS isolation device 12 can be,for example, a resistor. In FIG. 1B, the EOS protection device 11 isdisposed between the input contact 10 and ground. The EOS protectiondevice 11 can be disposed between the input contact 10 and any othersuitable low voltage reference. The EOS protection device 11 can be anESD protection device configured to provide ESD protection, for example.

The EOS sense device 14 is an EOS protection device. For instance, theEOS sense device 14 can be a high impedance scaled down version of theEOS protection device 11. The EOS sense device 14 can be arranged totrigger at a signal level at which an EOS event is considered to occur.A relatively small percentage of the EOS event current can be providedthrough the resistive element 15 for purposes of detecting a magnitudeof the EOS event. Accordingly, the signal provided to the detectioncircuit 16 by way of the EOS sense device 14 can be a scaled downversion of a signal associated with an EOS event.

The resistive element 15 can be electrically coupled between the EOSsense device 14 and ground. This can provide a voltage drop such that asignal provided to the detection circuitry can be at a lower voltagethan a voltage associated with the electrical overstress event, forexample. The resistive element 14 can have a relatively low resistance(for example, about 1 Ohm in certain applications) and consequently thedetection circuit 16 can receive a voltage signal that is at a lowervoltage level (for example, a few volts) than a voltage associated withthe electrical overstress event. The voltage drop provided by theresistive element 15 can prevent the detection circuit 16 from beingdamaged by the electrical overstress event.

As illustrated, the detection circuit 16 is electrically coupled to theEOS sense device 14 and configured to detect an occurrence of anelectrical overstress event. For example, the detection circuit 16 caninclude a comparator configured to compare a voltage associated with anelectrical over-stress event with a reference voltage. Such a comparatorcan generate an indication that an electrical overstress event hasoccurred. The detection circuit 16 can detect an intensity, such as avoltage level and/or a current level, associated with the electricaloverstress event using one or more comparators and/or ananalog-to-digital converter according to certain embodiments.

In certain embodiments, the detection circuit 16 can include circuitry,such as a counter circuit, to determine a duration of an EOS event. Theduration of an EOS pulse can be indicative of an amount of energyassociated with the EOS event. By detecting a duration of an EOS pulse,the detection circuit 16 can differentiate between different types ofEOS events, such as long DC pulses versus short transient pulses. Thedifferent types of EOS events can have varying impacts on the functionalsafety of an electronic system exposed to such EOS events. Accordingly,detecting the duration of an EOS event can provide additionalinformation about the functional safety of an electronic system incertain applications.

The detection circuit 16 can provide information indicative of anelectrical overstress event to the memory 17. The memory 17 can includeany suitable physical circuitry to store such information, such asvolatile memory or non-volatile memory. In certain embodiments, thememory 17 can include fuse elements. The memory 17 can store informationindicative of the EOS event. For example, the memory 17 can storeinformation indicative of an intensity of one or more EOS events,information indicative of a number of EOS events detected by thedetection circuit 16, information indicative of a type of EOS event,information indicative of a duration of an EOS event, the like, or anycombination thereof.

The reporting circuit 18 can provide information indicative of one ormore electrical over-stress events to external circuitry, such ascircuitry external to the electronic device 1. As illustrated, thereporting circuit 18 can receive such information from the memory 17. Insome other embodiments, the reporting circuit 18 can receive suchinformation from the detection circuit 16 without the information beingstored to memory of the electronic device 10 and report the information.The reporting circuit 18 can provide the information indicative of oneor more electrical overstress events to the output contact 19, which canbe a pin as illustrated. According to certain embodiments, the reportingcircuit 18 can wirelessly transmit such information and/or inductivelytransmit such information. The reporting circuit 18 can include theantenna transmission circuit 7 and/or the communication bus transmitter6 of FIG. 1A in certain embodiments.

Electrostatic discharge protection devices are examples of electricaloverstress protection devices, such as the EOS protection devices shownin FIG. 1B and/or other figures. FIGS. 2A to 2D illustrate exampleelectrostatic discharge protection devices that can be implemented inone or more embodiments. Any of the electrostatic discharge protectiondevices illustrated in FIGS. 2A to 2D can be implemented in connectionwith any suitable embodiment related to electrical overstress eventdetection, harvesting energy associated with an electrical overstressevent, configuring an electrical overstress protection device and/or astorage element responsive to an indication that an electricaloverstress event is likely to occur, or any combination thereof.

FIG. 2A illustrates diode-based ESD protection devices 20 a. FIG. 2Aillustrates a unidirectional blocking junction diode 20 a 1,series-forward blocking junction diodes 20 a 2 for proportional increaseof forward-biased conduction and reverse blocking voltage, antiparallellow voltage drop-conduction and decoupling diodes 20 a 3, and a highback-to-back diode-based bidirectional blocking device 20 a 4.

FIG. 2B illustrates bipolar transistor-based ESD protection devices 20 bincluding an NPN ESD device 20 b 1 and a PNP ESD device 20 b 2. Fromcollector to emitter (NPN) and emitter to collector (PNP), the bipolartransistors function as relatively high blocking voltage elements untilreaching a breakdown voltage, at which point the device triggers andprovides a low conduction path and high holding voltage between itsterminals. In the opposite voltage polarity, a forward-biased junctionis obtained.

FIG. 2C illustrates coupled unidirectional NPN and PNP thyristor-likeESD protection devices 20 c. The ESD protection devices shown in FIG. 2Ccan be referred to as semiconductor-controlled rectifiers. In someinstances, semiconductor-controlled rectifiers are silicon-controlledrectifiers (SCRs). The NPN and PNP thyristor-like ESD devices includeconfigurations with: floating NPN base 20 c 1, leading to a lowertrigger voltage; an NPN in collector-emitter breakdown voltage mode withbase-emitter resistance 20 c 2, leading to an intermediate triggervoltage; a traditional configuration with fixed base resistance 20 c 3for highest thyristor trigger voltage; and thyristor bipolar baseexternal latch trigger and latch release control 20 c 4.

FIG. 2D illustrates a coupled NPN-PNP-NPN bi-directional high blockingthyristor-like ESD protection device 20 d. The bidirectional breakdownvoltage in this device can be closely defined by the base-emitterjunction of the PNP device illustrated in the center of this device.

EOS events can be detected at various nodes in an electronic device inaccordance with the principles and advantages discussed herein. The EOSevent detection discussed herein can be sensed at a pin of an electronicdevice in certain embodiments. FIG. 3 is a schematic diagram of aportion of an illustrative electronic device 30 configured to detect anelectrostatic discharge event at a pin 31 of the electronic device 30according to an embodiment. As shown in FIG. 3, an ESD event can occurat the pin 31, which can be any suitable input/output (I/O) pin, and theESD event can be sensed at the pin 31. An ESD sense device 34 can bedisposed between the pin 31 and ESD event detection circuit 36, which isan example of the detection circuit 16 of FIG. 1B. The ESD eventdetection circuit 36 can provide information indicative of an occurrenceof an ESD event to a memory and/or reporting circuit (not illustrated)similar to in FIG. 1B. In FIG. 3, resistor 35 is disposed between theESD sense device 34 and ground. As illustrated, the resistor is alsodisposed between an input to the ESD event detection circuit 36 andground. An ESD protection device 33 can protect the ESD sense device 34and the resistor 35. The ESD protection device 33 can also protect anyother circuitry electrically connected to the pin 31. The ESD protectiondevice 33 is in parallel with the series combination of the ESD sensedevice 34 and the resistor 35 in FIG. 3. An ESD blocking/steering device32 can be disposed between the pin 31 and an internal circuit (notillustrated).

EOS events can alternatively or additionally be sensed across certaincircuit elements. Accordingly, information indicative of the functionalsafety of certain circuit elements can be recorded and/or reported. FIG.4 is a schematic diagram of a portion of an illustrative electronicdevice 40 configured to detect an electrostatic discharge event across astorage element according to an embodiment. In FIG. 4, energy associatedwith an ESD event can be stored as charge across a capacitor 48. Moredetails regarding such energy harvesting will be provided later. The ESDevent detection circuit 36 of FIG. 4 can detect an ESD event across thecapacitor 48. The ESD event detection circuit 36 of FIG. 4 can include acounter to track the number of ESD events detected across the capacitor48. The ESD event detection circuit 36 of FIG. 4 can detect an intensityof an ESD event, for example, by detecting a voltage across resistor 35associated with the ESD event. In FIG. 4, the first ESD protectiondevice 34 and the resistor 35 function similar to in FIG. 3. The firstESD protection device 34 can be a high impedance ESD protection device,which can be triggered by a level of an ESD event that is desired tomonitor. As such, the first ESD protection device 34 need not match theother illustrated ESD protection devices 33, 42, and/or 46 and/or thediode 44. The high impedance of the first ESD protection device 34 canlimit current through the resistor 35 and may conduct a relatively smallpercentage of current associated with an ESD event.

Various detection circuits 36 can be implemented to detect an EOS event.The detection circuit 36 can include any suitable circuit configured todetect an EOS. Four illustrative detection circuits 36 a, 36 b, 36 c,and 36 d will be described with reference to FIGS. 5, 6, 7, and 8,respectively. These detection circuits are example detection circuitsthat can be implemented in connection with any of the principles andadvantages discussed herein, for example, with reference to FIGS. 1, 3,and/or 4. Moreover, features of the any of the example detectioncircuits can be implemented in combination with any of the other exampledetection circuits.

FIG. 5 is a schematic diagram that includes a detection circuit 36 a andan ESD protection device 34 according to an embodiment. The detectioncircuit 36 a includes a comparator. As illustrated, the resistor 35 isdisposed between the ESD protection device 34 and ground. A voltagegenerated across the resistor 35 can be compared to a reference voltageV_(REF). The resistance of the resistor 35 and the reference voltage canbe selected such that ESD events above a threshold level trigger thecomparator to indicate that an ESD event has occurred. The resistance ofthe resistor 35 can be selected such that the voltage across theresistor 35 provided to the comparator is at a voltage level that isunlikely to damage the comparator. The comparator can be implemented byany suitable circuitry configured to detect when the voltage across theresistor 35 exceeds a threshold that indicates that an ESD event hasoccurred.

FIG. 6 is a schematic diagram that includes a detection circuit 36 b andan ESD protection device 34 according to another embodiment. Thedetection circuit 36 b includes a plurality of comparators 36 b 1, 36 b2, and 36bN that are each configured to compare the voltage across theresistor 35 to a different reference voltage (V_(REF1), V_(REF2), andV_(REFN), respectively). Any suitable number of comparators can beimplemented. Using the plurality of comparators 36 b 1, 36 b 2, and36bN, an intensity or level of an ESD event can be detected. The levelof the ESD event can correspond to the magnitude of the highestreference voltage provided to a comparator of the plurality ofcomparators that detects an occurrence of an ESD event. As such, thedetection circuit 36 b can detect an occurrence of an ESD event and anintensity of the ESD event.

FIG. 7 is a schematic diagram that includes a detection circuit 36 c andan ESD protection device 34 according to another embodiment. Asillustrated, the detection circuit 36 c includes a comparator 72, asample switch 74, and an analog-to-digital converter (ADC) 76. The ADC76 can be used to determine a level of an ESD event Like the detectorcircuit 36 a of FIG. 5, the comparator 72 can detect an occurrence of anESD event. Responsive to detecting an occurrence of an ESD event above alevel determined by the resistance of resistor 35 and the voltage levelof the reference voltage V_(REF), the output of the comparator 72 istoggled. This can cause the sample switch 74 to sample the voltageacross the resistor 35. The sampled voltage can be converted to adigital voltage level by the ADC 76. The output of the ADC 76 can beindicative of a level of the ESD event. As such, the detection circuit36 c can provide information associated with a detected ESD event, whichcan indicate an occurrence of the ESD event and a level associated withthe ESD event.

FIG. 8 is a schematic diagram that includes a detection circuit 36 d andan ESD protection device 34 according to another embodiment. Thedetection circuit 36 d is similar to the detection circuit 36 c except avoltage across the ESD protection device 34 is used to trigger thecomparator 72 and to detect a level of the ESD event. When the ESDprotection device 34 is triggered, it can go into snapback mode and holdat a holding voltage with a resistance. The holding voltage can be usedto detect an occurrence of an ESD event and the level of the ESD event.The ESD protection device 34 can be characterized and thencharacterization data can be used to determine the level of the ESDevent.

Various memories can store information indicative of an electricaloverstress event detected by the detection circuits discussed herein.Such memories can include non-volatile memories and/or volatilememories.

In certain embodiments, detecting an EOS can be implemented by memoryelements configured to store data under certain conditions. FIG. 9 is aschematic diagram of illustrative detection and memory circuit 90 thatis configured to detect and store information associated with an ESDevent according to an embodiment. The detection and memory circuit 90can implement the functionality of the detection circuit 16 and thememory 17 of FIG. 1B.

The detection and memory circuit 90 includes fuses. Fuses are one typeof non-volatile memory that can store data and/or alter thefunctionality of a device post manufacture. The detection and memorycircuit 90 includes fuse banks 92 and 94, a fuse bank selection circuit96, and a fuse bank reading circuit 98. The fuses of one or more of thefuse banks can be configured to blow at predetermined ESD event levels.Different fuses of a selected fuse bank can blow at different ESD eventlevels. The fuse bank reading circuit 98 can read from one or more ofthe fuse banks 92 and 94 to determine whether an ESD event has occurredand a level associated with the ESD event. For instance, if any of thefuses are blown, the occurrence of an ESD event can be detected. Thelevel associated with the ESD event can be detected based on whichfuse(s) are blown. The detection and memory circuit 90 can operate evenwhen an electronic device is not powered. The fuses can be one-timeprogrammable such that once a fuse in a fuse bank is blown, the fusebank selection circuit 96 can select a different fuse bank to detect anESD event. The detection and memory circuit 90 can detect ESD events ofboth a positive and a negative polarity. While FIG. 9 was described withreference to fuses for illustrative purposes, the principles andadvantages discussed with this figure can be applied to other fuseelements, such as anti-fuses, and/or to other memory elements that canbe selectively activated by different voltages.

EOS event detection can detect non catastrophic EOS events that age adevice without completely damaging the device. Such functionality canmonitor a circuit with slightly lower breakdown than other circuits andprovide aging information about the circuit. FIG. 10 is a schematicdiagram of a portion of an electronic device 100 with an ESD eventdetection circuit 36 according to an embodiment. The electronic deviceincludes a first ESD protection device 102 and second ESD protectiondevice 104.

The first ESD protection device 102 can be a diode having a relativelylow breakdown voltage and a relatively small physical area and thesecond ESD protection device 104 can be a diode having a relatively highbreakdown voltage and a relatively large physical area. These ESDprotection devices are illustrated as diodes, but other suitable ESDprotection devices can alternatively be implemented. The first ESDprotection device 102 can trigger at a lower voltage than the second ESDprotection device 104. In an illustrative example, the first protectiondevice 102 can trigger at about 6.5 Volts and the second ESD protectiondevice 104 can trigger at about 7 Volts. The second ESD protectiondevice 104 can handle more current than the first ESD protection device102. A resistor 35 can be in series with the first ESD protection device102, for example, to prevent thermal runaway and/or to provide a voltagefor the detection circuit 36.

With the first ESD protection device 102, ESD events below the thresholdfor triggering the second ESD protection device 104 can be detected andassociated data can be used to determine the age/state of “health” of apart. The ESD protection offered by the first ESD protection device 102may not be sufficient to protect an internal circuit, but the ESDprotection offered by the first ESD protection device 102 can provide away to monitor what is happening in the second ESD protection device 104without including a resistance, which should diminish the effectivenessof the second ESD protection device 104, in series with the second ESDprotection device 104.

The detection circuit 36 can detect an ESD event using the voltageacross the resistor 35. The detection circuit 36 can blow a fuse and/orload another memory each time an ESD event is detected. After a certainnumber of ESD events (e.g., 10 events) are detected, an alarm signal canbe provided. For instance, the alarm signal can be toggled when allfuses can be blown and/or memory cells can overflow. The alarm signalcan provide an alert to warn that a device has been aged by ESD events.

EOS detection circuitry can provide functional safety information at thedie level and/or at a system level. At the die level, recording andmonitoring EOS events can provide an indication of the functional safetyof the die. Such information can be reported external to the die. Analarm signal can be provided external to the die to provide a warningabout the functional safety of the die and/or to suggest that action betaken, such as replacement of the die. At the system level, detectingEOS events can provide information about functional safety at a systemlevel. Such information can be used for predictive maintenance, forexample.

Functional safety circuitry associated with detecting EOS events can beincorporated within a die and/or at a system level. For some expensiveand/or custom integrated circuit systems where reliability and/orquality is paramount, having the capability of sensing EOS events (e.g.,current surges and/or voltage surges applied from external to thesystem) and being able to provide information associated with thedetected EOS events can be advantageous. Such information can beprovided external to the integrated circuit system and/or can set analarm within the integrated circuit system to indicate that there is afunctional safety issue. Functional safety circuitry can be implementedin a variety of contexts including stacked die and/or prefabricatedlayers/components within a 3D vertically integrated system.

FIG. 11 is a diagram of stacked die 110 including a die 112 thatincludes functional safety circuitry according to an embodiment. Thestacked die 110 can include the die 112 stacked with one or more otherdie 114 a, 114 b, 114 c. The functional safety circuitry can implementany combination of features discussed herein associated with detectingan EOS event, storing information associated with the EOS event,reporting the EOS event, providing EOS and/or ESD protection, the like,or any combination thereof. For instance, the functional safetycircuitry of the die 112 can detect and record an overvoltage event oranother EOS event. In some instances, the functional safety circuitrycan record an intensity, a duration, a frequency, or any combinationthereof of the EOS event. The functional safety circuitry can transmitthe recorded information external to the stacked die 110 wirelessly byway of an antenna in an embodiment.

FIG. 12 is a diagram of a system in a package 120 that includesfunctional safety circuitry according to an embodiment. A die 112 thatincludes functional safety circuitry can be disposed on a circuit board122 with other components. The die 112 and the other components can beencased within a single package. The system in a package 120 can includean over mold compound 124 that encapsulates the die 112 and othercomponents. In this embodiment, the functional safety circuitry canprovide indicators as to the effective health of the system. Theindicators can be communicated externally from the system by the die 112and/or the other components, for example, wirelessly or by beingprovided to an output contact of the system in a package 120.

FIG. 13 is a diagram of an integrated circuit system 130 that includesfunctional safety circuitry according to an embodiment. The integratedcircuit system 130 can be arranged to provide functionality targeted toa variety of applications. For instance, the integrated circuit system130 can be an automotive electronics system configured for automotiveapplications (e.g., power steering). As another example, the integratedcircuit system 130 can be a vehicular electronics system, such as anavionics electronics system configured for aircraft applications. Inanother example, the integrated circuit system 130 can be a healthcareelectronics systems configured for healthcare monitoring (e.g.,monitoring a heart rate and/or monitoring another physiologicalparameter) and/or for other healthcare applications. The illustratedintegrated circuit system 130 includes the system in a package 120 ofFIG. 12 and other components on a system board 132. The functionalsafety circuitry of the system in a package 120 can provide informationindicative of potential failures with protection devices of theintegrated circuit system 130 that are external to the system in apackage 120. For example, a faulty diode of the integrated circuitsystem 130 might fail to prevent certain undesired static currentsand/or current surges. The functional safety circuitry of the system ina package 120 can monitor and record such EOS events. The functionalsafety circuitry can provide an external warning of such an issue. Thefunctional safety circuitry can provide an indication of a life span ofthe integrated circuit system 130.

Harvesting Energy from Electrical Overstress Events

As discussed above, aspects of this disclosure relate to harvestingenergy associated with electrical overstress events, such as ESD events.The energy harvesting discussed herein can be implemented in a varietyof contexts. For instance, energy harvesting can be implemented at a dieor chip level. This can result in a reduction of power consumption atthe die level, which can in turn reduce power consumption in a largersystem. As another example, energy harvesting can be implemented at asystem level, in a vertically integrated system of stacked die, or in anindustrial application. A system in a package that includes energyharvesting circuitry/structures can be included in a larger system. Asyet another example, energy harvesting can be implemented in a systemwith moving parts, such as rotating shafts, arranged to enhanceharvesting of charge associated with generated static charges/EOSevents.

Energy from EOS events can be stored by storage elements, such ascapacitor(s), and the charge can be provided to the system. Accordingly,energy associated with potentially damaging EOS events can be used topower circuits. Storage elements can be activated and/or deactivated asdesired. Circuitry can selectively enable and/or initiate storageelement activity. For example, portions of storage elements can bedischarged while other portions of storage elements can be charged.

The principles and advantages discussed in connection with harvestingenergy associated with EOS events can be implemented in connection withany of the principles and advantages discussed with reference todetecting and recording and/or reporting EOS events. Illustrativeembodiments related to harvesting energy from EOS events will now bediscussed.

An apparatus can include an EOS steering device and a storage elementconfigured to store charge associated with an EOS event, in which theEOS steering device can provide energy associated with an EOS event tothe storage element. The EOS device can be disposed between a pin of anelectronic device and the storage element. The storage element caninclude, for example, a capacitor. The EOS steering device can be ESDsteering device and EOS event can be an ESD event. A detection circuitcan be provided in combination with the storage element. The detectioncircuit can detect an EOS event.

FIG. 14 is a schematic diagram of an illustrative electronic device 140that is configured to store charge associated with an electricaloverstress event according to an embodiment. As illustrated, theelectronic device 140 includes an input contact 10, an EOS protectiondevice 11, an EOS steering device 142, an internal circuit 13, a storageelement 144, a load 148, and an output contact 149. The illustratedelements of the electronic device 140 can be included within a singlepackage. The electronic device 140 can include more elements thanillustrated and/or a subset of the illustrated elements. The electronicdevice 140 can be a die, for example. As such, in some instances, theillustrated elements of the electronic device 140 can be embodied on asingle die.

The electronic device 140 is configured to receive an input signal atthe input contact 10, which can be an input pin as illustrated. The EOSprotection device 11 is configured to provide protection from electricaloverstress events. The illustrated EOS protection device 11 isconfigured to protect the circuitry electrically connected to the inputcontact 10 by diverting current associated with an EOS event to groundwhen a signal on the input contact 10 exceeds an EOS capability of thedevices being protected, e.g., voltage breakdown. The EOS protectiondevice 11 can protect the internal circuit 13 and the storage element142 from electrical overstress events. In FIG. 14, the EOS protectiondevice 11 is disposed between the input contact 10 and ground. The EOSprotection device 11 can be disposed between the input contact 10 andany other suitable low voltage reference. The EOS protection device 11can be an ESD protection device configured to provide ESD protection,for example.

The EOS steering device 142 can direct energy associated with an ESDevent to the storage element 144 and to prevent charged stored by thestorage element 144 from escaping. The EOS steering device can beimplemented by any suitable ESD protection device, such as any of theESD protection devices discussed with reference to FIGS. 2A to 2D. TheEOS steering device 142 can be disposed between the input contact 10 andthe internal circuit 13. Alternatively, an ESD isolation device can bedisposed between the internal circuit 13 and the input contact 10similar to FIG. 1B. It can be desirable to have an intervening circuitelement between the internal circuit 13 and a pin from which energyassociated with an EOS event is being harvested.

The storage element 144 can include one or more capacitors and/or abattery. As illustrated, the storage element 144 is in series with theEOS steering device 142. The EOS protection device 11 is in parallelwith the series combination of the EOS steering device and the storageelement 144. The load 148 can be in parallel with the storage element144. In some embodiments, the voltage across the storage element 144 canbe regulated for providing to other circuitry. Charge from the storageelement can be provided to an output contact 149 of the electronicdevice 140. As such, energy harvested from an EOS event can be providedto circuitry external to the electronic device 140. Alternatively oradditionally, charge energy harvested from an EOS event can be providedto other circuitry within the electronic device, such as the internalcircuit 13, and/or to a battery of the electronic device.

FIG. 15 is a schematic diagram of an illustrative electronic device 150that is configured to store charge associated with an electricaloverstress event and to detect an occurrence of the electricaloverstress event according to an embodiment. The electronic device 150illustrates an example of how energy harvesting circuitry can becombined with detection circuitry configured to detect an EOS event.Another example in the context of ESD events is shown in FIG. 4.

FIG. 16 is a schematic diagram of a portion of an illustrativeelectronic device 160 configured to store charge associated with anelectrostatic discharge event according to an embodiment. The electronicdevice 160 provides bipolar performance of energy harvesting of ESDevents. As shown in FIG. 16, an ESD event can occur at pin 31. The ESDprotection device 161 can provide clamping for ESD events that exceedthe capacity of the system. ESD protection devices 162 and 163 provideare arranged in parallel with diodes 164 and 165, respectively, in FIG.16. The ESD protection devices 162 and 163 can provide ESD protectionfor diodes 164 and 165, respectively. In particular, these ESDprotection devices can each protect a respective diode from reversebreakdown. The diodes 164 and 165 are examples of the EOS steeringdevice 142 of FIGS. 14 and/or 15. The first diode 164 can steer currentto charge a first capacitor 166. The second diode 165 can steer currentof an opposite polarity to charge a second capacitor 167. Accordingly,charge associated with both positive and negative ESD events can bestored in a storage element that includes the capacitor 166 and 167. ESDprotection devices 168 and 169 can provide ESD protection for capacitors166 and 167, respectively.

FIG. 17 is a schematic diagram of a portion of an illustrativeelectronic device 170 configured to store charge associated with anelectrostatic discharge event in a bank of storage elements according toan embodiment. Multiple ESD events can occur. Such ESD events can havedifferent magnitudes. Having a bank of storage elements can enablecharge associated with different ESD events to be efficiently stored. Aplurality of switches 174 a to 174 d can each be arranged in series witha respective capacitor 172 a to 172 d. In an embodiment, a selected oneof the switches 174 a to 174 d can be on at a time. This can selectivelyelectrically connect a selected capacitor to the diode 164. Energyassociated with an ESD event at the pin 31 can be steered by the diode164 to capacitor of the plurality of capacitors 172 a to 172 d that iselectrically connected to the diode 164 by way of a switch. A voltagemonitoring circuit 176 can monitor the charge stored by each of thecapacitors 172 a to 172 d. The voltage monitoring circuit can detectwhich capacitor stores the least charge. A switch control circuit 178can turn on a selected switch based on information from the voltagemonitoring circuit 176. Having the capacitor storing the least chargeconfigured to capture charge associated with an ESD event can be anefficient way of capturing charge and can enable energy harvesting of asmany relatively small ESD pulses as possible.

Various circuits can store energy associated with an EOS event.Illustrative circuits configured to store charge associated with EOSevents will be described with reference to FIGS. 18 to 22. Thesecircuits provide examples of circuits that can harvest energy associatedwith EOS events in connection with any of the principles and advantagesdiscussed herein. Moreover, features of the any of the example energyharvesting circuits can be implemented in combination with one or moreother example energy harvesting circuits.

FIG. 18 is a schematic diagram of a circuit 180 configured to storecharge associated with an electrostatic discharge event according to anembodiment. As illustrated, the circuit 180 includes an input pin 31, adiode 182, a capacitor 184, a load 186, an output pin 188, and a groundpin 106. The diode 182 is an example of an EOS steering device 142 ofFIG. 14. The capacitor 184 is an example of a storage element 144 ofFIG. 14. When an ESD event occurs at the pin 31 and the ESD event has apositive polarity with respect to ground pin 106, the diode 182 can beforward biased and the capacitor 184 can be charged to a voltage. Thevoltage across the capacitor 184 can be approximately equal to theavailable charge divided by the capacitance of the capacitor 184. Oncethe voltage at the pin 31 drops below the voltage across the capacitor184, the charging phase can stop. The diode 182 can become reversebiased and the capacitor 184 can remain in a charged state. In theconfiguration illustrated in FIG. 18, the capacitor 184 can have abreakdown voltage in excess of a maximum expected voltage associatedwith an ESD event. The load 186 can be a resistive load, for example.The charge across capacitor 184 can be provided to other circuitry byway of output pin 188.

FIG. 19 is a schematic diagram of a circuit 190 configured to storecharge associated with an electrostatic discharge event according toanother embodiment. The circuit 190 provides clamping and voltageregulation. The circuit 190 is like the circuit 180 of FIG. 18 exceptthat an ESD protection device 192 is included. The ESD protection device192 can be arranged in parallel with the capacitor 184. The ESDprotection device 192 can function as an ESD clamp and/or protectiondevice. The ESD protection device 192 can ensure that the voltage on aplate of the capacitor 184 opposite ground is clamped to a voltage belowthe breakdown of the capacitor 184. The ESD protection device 192 canfunction is as a voltage regulator. When an ESD event is over, the ESDprotection device 192 can shut current to ground GND until the voltageacross the capacitor 184 is at approximately the breakdown voltage ofthe ESD protection device 192. In a specific example, if the ESDprotection device 192 has a breakdown voltage of 5 Volts, once the ESDevent is over the ESD protection device 192 can shunt current to groundGND until the voltage across the capacitor 184 is approximately 5 Volts.Accordingly, the voltage stored on the capacitor 184 can be regulated toa voltage safe to be used by downstream circuits. The ESD protectiondevice 192 can be a Zener diode as illustrated.

FIG. 20 is a schematic diagram of a circuit 200 configured to storecharge associated with an electrostatic discharge event according toanother embodiment. The circuit 200 provides clamping and voltageregulation. In FIG. 20, the ESD protection device 192 of FIG. 19 isreplaced by an ESD clamp circuit 202. As illustrated, the ESD clamp cell202 can be a stack of Zener diodes. As one example, the stack of Zenerdiodes can clamp the voltage across the capacitor 184 to approximately20 Volts. The ESD clamp circuit 202 can be implemented by any suitableESD clamp circuit such as NPN ESD device, an SCR, etc. A separatevoltage regulator can be implemented, for example, by transistor 203,diode 204, and resistor 206. Any other suitable voltage regulator canalternatively be implemented. Moreover, such a voltage regulator canprovide any suitable regulated voltage for a particular application.

FIG. 21 is a schematic diagram of a circuit 210 configured to storecharge associated with an electrostatic discharge event according toanother embodiment. FIG. 21 illustrates that the charge stored inconnection with an ESD event can be provided to a battery 212 torecharge the battery 212. Accordingly, energy harvested from an ESDevent can be stored on a storage element, voltage can be regulated, andthe battery 212 can be recharged using energy harvested from the ESDevent.

FIG. 22 is a schematic diagram of a circuit 220 configured to storecharge associated with an electrostatic discharge event according toanother embodiment. An EOS energy harvester can work in a similar way tohow a radio receiver works. As shown in FIG. 22, a basic diode detectorused for AM radio can implement diode 182. The diode 182 can receive asignal from the antenna 222 and the capacitor 184 can store chargeassociated with an EOS event. The diode 182 can be a crystal diode asillustrated in FIG. 22. Features of FIG. 22 can be combined with avoltage regulator and the energy stored by the capacitor 184 can beprovided to other circuits and/or a battery, for example, as describedabove. Moreover, the features of FIG. 22 can be combined with adetection circuit configured to detect that an EOS event has occurred.Such a detection circuit can be implemented in accordance with theprinciples and advantages of the detection circuits discussed herein.

Energy harvesting circuits as discussed herein can be implemented in avariety of electronic systems. For example, such circuits can beimplemented in vertically integrated systems. The energy harvestingcircuitry can be implemented on a dedicated die or layer of a verticallyintegrated system, such as the die 112 in FIG. 11. Energy harvestingcircuitry can be implemented at least partly on a layer in a verticallyintegrated system that includes prefabricated circuit elements, such aspassives. Energy harvesting circuitry can be implemented at anintegrated circuit level, at a system in a package level, at largersystem level, or any combination thereof. When energy harvestingcircuitry is implemented at a system level, die area may not be alimiting factor. Accordingly, relatively large EOS protection devicescan provide higher than typical current density capabilities.Alternatively or additionally, relatively less complicated devices canbe implemented at a system level, such as larger reverse biased diodes.Moreover, relatively high EOS protection can be provided at a systemlevel and a higher level of charge may be captured than at a die levelin certain applications.

Certain physical layouts of ESD protection devices can be implementedfor high performance. The physical layouts discussed below can beimplemented in connection with any of the EOS protection devicesdiscussed herein. Example physical layouts are illustrated in FIGS. 23Ato 23C.

FIG. 23A provides an example of a physical layout of an ESD protectiondevice 230. In FIG. 23A, the ESD protection device is an annularstructure in plan view. This can enable relatively high current handlingcapability. Anode 232 and cathode 234 of the ESD protection device 230can be provided around a bond pad 236. The weakest point of an ESDprotection device can be at the end of a finger, even with increasedspacings, resistances and/or curvature, as this is the location of thattypically has the highest electric field. An annular ESD siliconcontrolled rectifier (SCR) can be used for system level ESD protectionto mimic a circular device enclosing a bond pad. Such a SCR can includeany combination of features described in U.S. Pat. No. 6,236,087, theentire technical disclosure of which is hereby incorporated by referenceherein.

An annularly shaped ESD protection device in plan view can have arelatively large perimeter area and hence a relatively large crosssectional area through which the current can flow. As one example, theperimeter can be about 400 μm and the diode junction can be about 3 μmdeep, thus the cross section area can be about 1200 μm². Additionally,with the annular structure, metal can come out from a bond pad on foursides. This can combine to substantially minimize the resistance to anESD zap and hence the voltage experienced by sensitive circuitryinternal in the chip can be substantially minimized. Another approachthat may provide an even lower resistance path to an ESD zap is a purevertical diode where the conduction is vertically down through thesilicon. In such a diode, for a 100 μm by 100 μm pad, the cross sectionarea is 10,000 μm² and the metal resistance can also be relatively smallas there can be a thick low resistance metal paddle on one side and alow resistance bond wire in close proximity on the other side.

In some instances, an ideal ESD device can be circular, as substantiallythe same electric field can be present along the entire a junction insuch a structure. Circular ESD device layouts may not be area efficientand/or an inner anode can be smaller in junction area than an outercathode. Circular ESD device layouts can conduct larger currents thansome other common ESD layouts that consume approximately the same area.Circular ESD device layouts can conduct relatively large currents, suchas currents associated with EOS events. Accordingly, such ESD devicelayouts can be desirable in certain applications in which an ESD deviceis used to harvest energy associated with an EOS event.

FIG. 23B provides an example of a physical layout of an ESD device 237.The physical layout of the ESD device 237 is a relatively large circularshape in plan view. This can reduce the difference between junction areabetween the anode 232 and the cathode 234.

FIG. 23C provides an example of a physical layout of an ESD device 238.The ESD device 238 is implemented by a relatively dense array of smallercircular ESD devices 239. The smaller circular ESD devices 239 can bebutted against each other laterally and/or vertically. An array ofsmaller circular ESD devices 239 can be implemented in wearablecomputing devices such as smart watches, for example.

FIG. 24 illustrates another ESD protection device 240 where the currentsurge is conducted vertically through to the layer below. In the ESDprotection device 240, current can be dissipated to ground throughsurface 244 below N region 242. Considering the N region 242 as a halfcylinder, the ESD protection device 240 can be capable of carrying alarger current compared to an annular ESD protection structure, as theESD protection device 240 has a larger area 244 than a correspondingannularly shaped ESD protection device. These principles can be appliedwhen optimizing the current carrying capabilities of the structuresharnessing the ESD zaps/current surges.

The illustrative energy harvesting circuits of FIGS. 14 to 22 can beembodied in a variety of integrated circuit systems. Examples of suchintegrated circuit systems will be discussed with reference to FIGS. 25to 30B.

In some embodiments, scaled up structures capable of harnessing an EOSevent for storing charge associated with the EOS event can be providedwithin a vertically integrated system. FIG. 25 provides an example of avertically integrated system 250 with such functionality. The verticallyintegrated system 250 can include segregated and/or scaled up EOSprotection devices so that it can handle larger surges and/or to linkwith a storage layer. The vertically integrated system 250 includes anESD protection layer 252, an insulating layer 254, and a storage layer256. The ESD protection layer 252 can include ESD protection devices. Insome embodiments, the ESD protection layer 252 can include a detectioncircuit to detect an ESD event. The ESD protection layer 252 can includecoils 253 or other structures that enable signals to be sent wirelesslyexternal to the vertically integrated system 250. Alternatively oradditionally, one or more other layers of the vertically integratedsystem 250 can include coils 253 or other structures that enable signalsto wirelessly be sent external to the vertically integrated system 250.The coils or other structures can send information indicative of an ESDevent and/or a warning that an external system safety protection isfaulty. The insulating layer 254 can serve to insulate the ESDprotection layer 252 from the storage layer 256. One or more vias 255and/or other electrical paths can allow charge to flow from the ESDlayer to the storage layer 256. The storage layer 256 can include oneany of the storage elements discussed herein, such as one or morecapacitors and/or other storage elements configured to store chargeassociated with an ESD event. Charge stored in the storage layer 256 canbe provided to other circuits.

FIG. 26 is a schematic diagram of a vertically integrated system 260that includes ESD protection and energy harvesting circuitry accordingto an embodiment. The vertically integrated system 260 includes an ESDprotection chip 261, a storage chip 263, and an application specificintegrated circuit (ASIC) 264 having an active side 265. Wire bonds 266can provide electrical connections to the ESD protection chip 261 and/orthe ASIC 264. A mold compound 267 can encase the other illustratedelements within a single package. The ESD protection chip 261 caninclude ESD protection devices configured to provide energy associatedwith ESD events to storage elements of the storage chip 263. Asillustrated, the ESD protection chip 261 and the storage chip 263 arearranged in a vertical stack with the ASIC 264. Insulating layers 262,such as dielectric or other die attach layers, are illustrated betweenthe different chips in FIG. 26.

By having ESD protection devices on a separate chip from the ASIC 264,the ESD protection devices can be configured to handle ESD events havinga greater magnitude than if the ESD protections devices were to beincluded on the ASIC 264. The ESD protection chip 261 is electricallyconnected to the storage chip 263. The storage chip 263 can beelectrically connected to the ASIC 264. The electrical connectionsbetween chips in FIG. 26 can include wire bonds, through silicon vias,etc. The storage layer 263 can power the operation of the ASIC 264 usingenergy harvested from an ESD event. The integrated circuit system 260can provide a system within a package where externally generated EOSevents can be used to power the ASIC 264. Even if a relatively smallamount of power is harvested from EOS events, the cumulative reductionin total system power can be significant in time if the total systemincluded a relatively large number (e.g., hundreds or thousands) ofvertically integrated systems.

FIG. 27 is a schematic diagram of a vertically integrated system 270that includes ESD protection and energy harvesting circuitry on a singlechip according to an embodiment. A combined ESD protection and storagechip 272 includes circuitry capable of harnessing energy from ESD eventsand storage elements configured to store charge associated with the ESDevents. Combined ESD protection and storage chip 272 can be stacked withan ASIC 264. Combining the ESD protection devices and storage elementsin a single die can reduce height of the vertically integrated systemrelative to two separate die stacked in a pyramid configuration.Combining the ESD protection devices and storage elements in a singledie can reduce the length and/or resistance of a path from a surgeconduction point and storage elements relative to two separately stackeddie. The ASIC 264 can receive charge from storage elements of thecombined ESD protection and storage chip 272. Having the energyharvesting circuitry on a different chip than the ASIC can allow EOSprotection devices, such as ESD protection devices, to be scaled up tostore charge from larger EOS events, such as larger ESD events.

FIG. 28 illustrates a die 280 with EOS protection devices 282, storageelements 284, and processing circuitry 286 according to an embodiment.At a micro level, the EOS protection devices 282 can be segregated fromthe storage elements 284 and the processing circuitry 286 within thesame die 280. In the illustrated embodiment, the die 280 iscompartmentalized to deliver a system within a chip where the storageelements 284 are electrically connected to the processing circuitry 286as a power source. As illustrated, the die 280 is partitioned intoconcentric type sections. The different sections of die 280 can becombined on a single semiconductor substrate, such as a siliconsubstrate. Trench isolation type fab processes where selective portionscan be isolated from the substrate can be used to manufacture thedifferent sections of the die 280.

FIG. 29 illustrates a die 290 with EOS protection devices 282, storageelements 284, and processing circuitry 286 according to an embodiment.The die 290 includes a compartmentalized arrangement where the differentsections of circuitry 282, 284, 286 are separated by an isolationbarrier 292 and configured in a side by side arrangement. The isolationbarrier 292 can include trench isolation. The trenches can includesinsulating material, such as dielectric material. In an embodiment, anisolation layer can be included around some or all of the EOS protectiondevices of a compartmentalized die. Alternatively or additionally, aninsulating layer, such as a dielectric layer, can cover the EOSprotection devices 282 and/or the storage elements 284.

Energy harvesting circuitry can be implemented in mobile and/or wearabledevices. FIGS. 30A and 30B illustrate an embodiment of a mobile device300 that includes an external casing 302 having conduits 304 embeddedwithin the external casing 302. Mobile devices, such as mobile phonesand/or other handheld devices, can include conduits 304 that arearranged for harvesting external sources of charge, such as staticcharge. As shown in FIG. 30B, electrical connections 306 can routecharge from conduits 304 to energy harvesting circuitry. The energyharvesting circuitry can be embodied in a system in a package 120 asillustrated. The external casing 302 can be configured to enhance and/oroptimize the delivery of charge to the energy harvesting circuitryincluded within the external casing 302 of the mobile device.

Any combination of features of the mobile device 300 can be applied toany suitable wearable device, such as a smart watch and/or a wearablehealthcare monitoring device. For instance, any of the principles andadvantages of the embodiments of FIGS. 30A and/or 30B can be applied toa wearable device. FIG. 30C illustrates a wearable device 305 with anexternal casing 302 and conduits 304. The wearable device 305 can beconfigured to be in contact with skin. The conduits 304 on the externalcasing 302 can be arranged to enhance and/or optimize the harvesting ofcharge from EOS events from external sources. The shape and/orarrangement of materials of the conduits 304 can enhance and/or optimizethe harvesting of charge. For instance, any of the conduits 304 in anyof FIGS. 30A to 30C can implement one or more features discussed inconnection with FIG. 31 and/or FIGS. 33A to 33D.

In an embodiment, an energy harvesting system can be implemented inwearable device or another portable electronic device. The energyharvesting system can include conduits, ESD protection circuitry, astorage layer and a configuration circuit. The conduits can be arrangedto efficiently channel ESD energy from an external source, such as ESDenergy from contact with a person. The ESD protection circuitryconfigured to prevent a current spike and/or a voltage spike associatedwith an ESD event from damaging to other circuitry within the system. Astorage layer can be configured to store the charge associated with theESD event. The configuration circuit can configure the storage elementswithin the storage layer as desired to store charge associated with anESD event.

The storage layer can also include ESD protection devices. The storagelayer configuration circuit can control switches of the storage layer toselect which storage element(s), such as capacitor(s), of the storage inwhich to store change associated with an ESD event. When one storageelement is fully charged, the storage layer configuration circuit canadjust the state of switches such that charge associated with asubsequent ESD event is stored in another storage element. The conduitscan be arranged such that the charge can only flow in one direction. Theconduits can be configured to carry the maximum charge as efficiently aspossible (e.g., in a circular or annular construction). The system caninclude a proximity sensor configured to detect a charged body.Responsive to detecting the charged body, the EDS protection circuitrycan be configured and/or enabled. The system can include circuitry torecirculate charge from a storage element within the system and/orexternal to the system.

FIG. 31 illustrates examples of conductive structures of in an opening311 of a package 312 to ESD protection devices 314 according to variousembodiments. A conductive via 315 can be incorporated within the package312 to provide signals associated with ESD events to an ESD protectiondevice 314. Alternatively or additionally, conductive via 316 can beincorporated within the package 312 to provide signals associated withESD events to an ESD protection device 314. Alternatively oradditionally, a conductive connector 317 can be incorporated within thepackage 312 to provide signals associated with ESD events to an ESDprotection device 314. The conductive structures of FIG. 31 are examplesof electrical paths that can be enhanced and/or optimized for providinga signal associated with an ESD event for purposes of energy harvesting.

In some embodiments, electrical energy generation can result fromrotating shafts and/or moving machine parts, for example, in industrialapplications, vehicles, etc. Energy from electrical fields and/or staticcharge generated by rotating shafts and/or in industrial applicationscan generate electrical field flow and mobile carriers that can bestored by storage elements in accordance with the principles andadvantages discussed herein. Example embodiments will be discussed withreference to FIGS. 32 to 33D.

FIG. 32 illustrates a system 320 that includes a rotating shaft 322 anda charge harvesting system 324 according to an embodiment. Rotation ofthe shaft 322 is a potential source of an electrical field and/or astatic charge. The charge harvesting system 324 can include structuresconfigured to conduct, store, and process the charge generated byrotation of the shaft 322. The charge harvesting system 324 can beplaced at or near an optimal proximity to the shaft 322 for purposes ofcapturing charge. The charge harvesting system 324 can be in contactwith the shaft 322 or a material thereon in certain applications. Thecharge generated and stored within the charge harvesting system 324 canthen be re-circulated and/or used for another function and/or to powercomponents within the charge harvesting system 324.

The charge harvesting system 324 can harvest energy from parts, such asshafts, that move to perform other functions. Accordingly, energy thatwould otherwise be lost in a system can be captured by the chargeharvesting system 324. Existing equipment and/or machinery can beretro-fitted with a charge harvesting system 324 to capture charge andre-circulate the captured charge to the system. Charge harvestingsystems 324 can be incorporated into smart vehicles and/or electricvehicles such that, in certain circumstances (e.g., moving parts due tokinetic energy and/or physical momentum associated with going down ahill), charge can be generated and then stored and re-circulated withinthe vehicle.

The amount of charge generated by moving and/or rotating machinery canbe enhanced and/or optimized by material selection. Materials used toconstruct moving parts can be selected along with other materials placedin close proximity to improve the intensity of the generated electricalfield and/or amount of generated charge.

FIG. 33A illustrates a rotating shaft 322 having a layer of material 332for enhancing an ESD field and/or charge generated by the rotating shaftand a charge harvesting system 324 having a layer of material 334 forenhancing an ESD field and/or charge generated. Surfaces of material 332and the charge harvesting system 324 can be in physical contact witheach other for an ESD field from the rotating shaft to be discharged tothe charge harvesting system. Alternatively, the material 332 and thecharge harvesting system 324 can be in close proximity to each other anda large enough charge to enable air-gap arcing can cause discharge fromthe rotating shaft to the charge harvesting system. Materials 332 and334 can be selected and/or shaped to enhance and/or optimize chargegenerated by the shaft 332 and stored by the charge harvesting system324. As shown in FIG. 33A, the rotating shaft 322 can have the layer ofmaterial 332 disposed around the circumference of the shaft 322. Forinstance, the layer of material 332 can be a ring and/or collar. Thematerial 332 can be selected such that it maximizes the field generatedwhen the shaft 322 is rotated in close proximity to the chargeharvesting system 324, which can include another material layer 334 thatcan be exposed to the material 332. The charge harvesting system 324 canharvest ESD energy and can conduct the generated charge to the layerswithin the system. The charge can be stored in any of the storageelements discussed herein. The stored charge can then be circulatedand/or applied to power up other operations within the charge harvestingsystem 324 and/or external to the charge harvesting system 324.

FIG. 33B illustrates that the layer of material 332′ incorporated on therotating shaft 322 can have a non-uniform width in certain embodiments.The width of the layer of material 332′ can have a varying width asillustrated. The change in the width of the layer of material 332′ canproduce a discernible shift in the generated electric field between thelayer of material 332′ and the layer of material 334, which can bedetected by the energy harvesting system 324. This measured change inthe electrical field can be used in a number of ways, including tomeasure the revolutions per unit time of the shaft 322 based on thediscernible change in electric field between the layers of material 332′and 334 as the shaft 322 rotates and/or to intentionally use thechanging and/or intermittent peak nature of the electric field toelectrically manipulate/move/operate the layers within the chargeharvesting system 324 at defined periodic intervals.

FIG. 33C illustrates a selected surface topography of the layer ofmaterial 334′ of the energy harvesting system 324 according to anembodiment. The topography of the layer of material 334′ can be modifiedrelative to a planar layer to increase the surface area of the materialexposed to the rotating shaft 322, for example, as illustrated.Accordingly, the electric field generated can be increased.

FIG. 33D illustrates a surface finish 336 on the layer of material 334′of the energy harvesting system 324 according to an embodiment. Recessesin the layer of material 334′ can be filled with a surface finishmaterial 336 to enhance and/or optimize charge associated with ESDevents. The surface finish material 336 can be selected to optimizecharge and/or electric field generated relative to the layer of material332′. Accordingly the interaction and/or shape of the materials of thelayers 332′ and/or 334′ and/or the surface finish 336 can optimize theelectric field generated by the rotating shaft 322.

Various patterns and/or arrangements of the materials 332 and/or 334 canbe implemented to enhance and/or optimize properties of electric fieldsand/or other electrical effects generated by the rotating shaft 322.Example patterns include concentric shapes, such as concentric circlesor concentric squares, pyramidal stacked layers, rows of material withanother material disposed over the rows of material, the like, or anycombination thereof.

When two different materials are pressed or rubbed together, the surfaceof one material can generally capture some electrons from the surface ofthe other material. The material that captures electrons can have astronger affinity for negative charge of the two materials, and thatsurface can be negatively charged after the materials are separated. Ofcourse, the other material should have an equal amount of positivecharge. If various insulating materials are pressed or rubbed togetherand then the amount and polarity of the charge on each surface isseparately measured, a reproducible pattern can emerge. For insulators,Table 1 below can be used to predict which will become positive versusnegative and how strong the effect can be. Such materials can beselected for purposes of generating charge in the embodiments of FIGS.33A to 33D. Electroactive polymers are some other examples of materialsthat can be used in generating charge. Polarization can be inducted byelectric field and polarization can modify the electric field.Accordingly, polarization can modify an intensity of an electric field.

TABLE 1 Typical Material Correction Factors Material Correction FactorType of Metal Steel (Fe360) 1.0 Ferrous Stainless Steel 0.6 . . . 1.0Non-Ferrous Aluminum 0.30 . . . 0.45 Non-Ferrous Brass 0.35 . . . 0.50Non-Ferrous Copper 0.25 . . . 0.45 Non-Ferrous

Any of the principles and advantages described in connection withmaterials and/or patterns/arrangements of materials to enhance and/ormaximize electric fields/generated charge can also be applied to monitorsystem utilization. For example, where the change in electric fieldgenerated by a material and/or a pattern/arrangement of materials can beproportional to a state, such as a particular state of operation of thesystem, information indicative of the state can be communicated remotelyfrom the system. Such information can be used in monitoring the system.

The principles and advantages discussed herein with reference toharvesting energy from EOS events can be applied to a variety ofcontexts in which an object carrying charge approaches another object.The object carrying charge can provide the EOS. For example, FIG. 33E isa block diagram of a context in which energy harvesting can beimplemented according to an embodiment. In FIG. 33E, a vehicle 335 canapproach a docking station 336. The docking station 336 can include EOSprotection circuits and circuits to be protected. The docking station336 can include energy harvesting circuitry and/or EOS detection andrecording circuitry. The charge harvested by the docking station 336 canbe used to power circuits of the docking station. In an embodiment,static charge generated by the vehicle 335 can be used to charge anelectric vehicle, for instance, when the docking station 336 can performa charging function. The vehicle 335 can include structures/materials337 that can be configured to enhance and/or optimize a generated fieldin combination with another structure/material 338 associated with thedocking station 338. The structures 337 and/or 338 can implement one ormore features discussed above, for example, in connection with arotating shaft. The vehicle 335 can include functional safety circuitryin certain implementations.

Responsive to detecting the vehicle 335 approaching the docking station336, the energy harvesting circuitry and/or EOS detection and recordingcircuitry can be enabled and/or pre-conditioned. A proximity sensor,such as discussed below, can detect that the vehicle 335 (e.g., a car, atruck, a subway train, a train, a forklift, etc.) is approaching thedocking station 336.

Smart storage aspects of harvesting changed associated with EOS events,such as switching on and off different capacitors, enabling protectivecircuitry, the act of sensing the presence of something, can be appliedin a variety of contexts. For example, in the case of a smart/electricvehicle, smart storage circuitry, such as the storage circuitry of theelectronic device 170 of FIG. 17, can be incorporated within a systemwhereby the charge/storage levels are recorded and/or transmittedwirelessly to implement a variety of functionalities. For instance, afleet of “smart” forklifts/vehicles could be managed/monitored, forexample, when stored charge of a specific vehicle gets to a certainlevel, the system can flags this and initiate a plans for the specificvehicle to recharge. As another example, within a “smart” vehicle when astorage level gets to a certain level this enables a “smarter” use ofsystem power, such as temporarily turning off non-essentialfunctionality. As another example, before/during docking a level ofpower within the storage system can be remotely transmitted to thedocking station and this can enables more effective charging/energymanagement at the docking station. In another example, energy harvestingcircuitry can harness and store the charge carried by a vehicle for useby the vehicle. In one other example, a docking station can harveststatic charge generated by a vehicle and used the harvested charge toperform a charging function.

Energy harvesting circuitry and/or storage elements can be physicallyimplemented in a variety of ways. FIGS. 36 to 41 provide illustrativephysical embodiments of energy harvesting circuitry configured to storeenergy associated with EOS events in storage elements. Any of theseembodiments can include EOS event detection circuitry. In theseembodiments, exposed surfaces of EOS can, for example, include circularconducting structures or arrays of such circular conducting structures.Any of the principles and advantages discussed with reference to energyharvesting and storage layers, such as circuits, materials, layers,etc., can be implemented in connection with any of FIGS. 36 to 41.

In FIG. 36, electronic device 360 includes EOS protection layers 252 onopposing sides. The EOS protection layers 252 in this electronic devicecan harvest change on opposing sides of the electronic device. The EOSprotection layers 252 can include EOS devices and/or other circuitry forgenerating charge associated with EOS events. Each of the EOS protectionlayers 252 can be connected to the storage layer 256, which includesstorage elements to store the harvested charge. Insulating material canbe included between each of the EOS protection layers 252 and thestorage layer 256. In another embodiment, separate storage layers can beincluded for each EOS protection layer 252. As illustrated, theelectronic device 360 also includes an ASIC 264.

In FIG. 37, the electronic device 370 includes side by side EOSprotection layers 252. As illustrated, each of these EOS protectionlayers 252 are in electrical communication with a respective storagelayer 256. The illustrated electronic device 370 includes separatevertical stacks of an EOS protection layer 252, a storage layer 256, andan ASIC 264.

The electronic device 380 of FIG. 38 includes an opening 382 throughwhich EOS devices of the EOS layer 252 are exposed. Such a device can beused in a variety of different EOS event detection and/or EOS eventharvesting applications.

The electronic device 390 of FIG. 39 includes an opening 392 throughwhich EOS devices of the EOS layer 252 are exposed at the bottom of arecess. Such a device can be used in a variety of different EOS eventdetection and/or EOS event harvesting applications.

The electronic device 400 of FIG. 40 includes EOS devices of EOS layers252 within an opening between two sides of an embedded structure. Such adevice can be used in a variety of different EOS event detection and/orEOS event harvesting applications.

The electronic device 410 of FIG. 41 includes EOS devices of EOS layers252 within an opening/recess of an embedded structure. Such a device canbe used in a variety of different EOS event detection and/or EOS eventharvesting applications.

Proximity of an Electric Field and EOS Protection and/or EnergyHarvesting Configuration

As discussed above, aspects of this disclosure relate to detectingproximity of an electrical field and configuring circuitry for EOSprotection and/or harvesting energy from an EOS event responsive todetecting proximity. Proximity sensing information can be used toconfigure EOS protection circuitry and/or energy harvesting circuitryconfigured to store energy associated with EOS events. Proximity sensinginformation can indicate proximity of an object in one, two, or threedimensions. The principles and advantages associated with usingproximity sensing information to configure devices can be applied inconnection with any of the other embodiments discussed herein.Illustrative embodiments related to proximity sensing will now bediscussed.

FIG. 34 is a schematic block diagram of an illustrative electronicdevice that can configure EOS protection using proximity sensinginformation according to an embodiment. As illustrated, the electronicdevice 340 includes an input contact 10, an EOS protection device 11, aproximity sensor 342, and an EOS configuration circuit 344. Theproximity sensor 342 can be any suitable sensor configured to senseproximity of an object to the electronic device 340. For instance, theproximity sensor 342 can be a capacitive sensor or a magnetic sensor incertain implementations. The proximity sensor 342 can provide proximityinformation to the EOS configuration circuit 344. The EOS configurationcircuit 344 can enable EOS protection. The EOS configuration circuit 344can configure the EOS protection device 11 based on the proximityinformation. Accordingly, the EOS protection device can be configuredprior to an EOS event resulting from an object in proximity to theelectronic device. The EOS configuration circuit 344 can, for example,provide active voltage clamping of the EOS protection device 11 and/orprovide current to an actively controlled protection circuit, such as anactively controlled SCR.

According to certain embodiments, the EOS protection device 11 can be anESD protection device. The EOS configuration circuitry 344 canpre-trigger and/or prime the ESD protection device to trigger responsiveto the proximity information indicating that an ESD event is likelyimminent. When there is a race condition between the ESD protection andthe internal circuits to be protected, such pre-triggering and/orpriming can ensure proper ESD protection of the internal circuits.Pre-triggering an ESD protection device can provide more robust ESDprotection for fast ESD events, such as ESD events on the order ofnanoseconds or less.

FIG. 35 is a schematic block diagram of an illustrative electronicdevice that can configure a storage element arranged to store energyassociated with an EOS event using proximity sensing informationaccording to an embodiment. As illustrated, the electronic device 350includes an input contact 10, an EOS protection device 11, an EOSsteering device 142, a storage element 144, a load 148, an outputcontact 149, a proximity sensor 342, and a storage element configurationcircuit 354. In FIG. 35, the proximity sensor 342 can provide proximityinformation to the storage element circuit 344. The storage elementconfiguration circuit 354 can configure the storage element 144 based onthe proximity information. Accordingly, the storage element 144 can beconfigured prior to an EOS event resulting from an object in proximityto the electronic device. Based on the proximity information, particularcapacitor(s) and/or other storage structure(s) of the storage element144 can be switched in to capture charge associated with the EOS event.The particular capacitor(s) and/or other storage structure(s) that areswitched in based on capacity to capture energy associated with an EOSevent. The particular capacitor(s) and/or other storage structure(s) canlater be switched out after the charge associated with the EOS event iscaptured.

CONCLUSION

In the embodiments described above, apparatus, systems, and methods forreference switchover are described in connection with particularembodiments. It will be understood, however, that the principles andadvantages of the embodiments can be used for any other systems,apparatus, or methods with a need for smooth reference switchover.Although certain embodiments are described with reference a localcrystal oscillator, it will be understood that the principles andadvantages described herein can be applied to signals generated by otheroscillators. While the disclosed embodiments may be described withreference to two redundant clocks, the principles and advantagesdiscussed herein can be applied to systems with three or more redundantclocks. Moreover, while some logic circuits are provided forillustrative purposes, other logically equivalent circuits canalternatively be implemented to achieve the functionality describedherein.

The principles and advantages described herein can be implemented invarious apparatuses. Examples of such apparatuses can include, but arenot limited to, consumer electronic products, parts of the consumerelectronic products, electronic test equipment, etc. Examples of partsof consumer electronic products can include clocking circuits,analog-to-digital converts, amplifiers, rectifiers, programmablefilters, attenuators, variable frequency circuits, etc. Examples of theelectronic devices can also include memory chips, memory modules,circuits of optical networks or other communication networks, and diskdriver circuits. Consumer electronic products can include, but are notlimited to, wireless devices, a mobile phone (for example, a smartphone), cellular base stations, a telephone, a television, a computermonitor, a computer, a hand-held computer, a tablet computer, a laptopcomputer, a personal digital assistant (PDA), a microwave, arefrigerator, a stereo system, a cassette recorder or player, a DVDplayer, a CD player, a digital video recorder (DVR), a VCR, an MP3player, a radio, a camcorder, a camera, a digital camera, a portablememory chip, a washer, a dryer, a washer/dryer, a copier, a facsimilemachine, a scanner, a wrist watch, a smart watch, a clock, a wearablehealth monitoring device, etc. Further, apparatuses can includeunfinished products.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,”“include,” “including,” and the like are to be construed in an inclusivesense, as opposed to an exclusive or exhaustive sense; that is to say,in the sense of “including, but not limited to.” The words “coupled” orconnected”, as generally used herein, refer to two or more elements thatmay be either directly connected, or connected by way of one or moreintermediate elements. Additionally, the words “herein,” “above,”“below,” and words of similar import, when used in this application,shall refer to this application as a whole and not to any particularportions of this application. Where the context permits, words in theDetailed Description using the singular or plural number may alsoinclude the plural or singular number, respectively. The words “or” inreference to a list of two or more items, is intended to cover all ofthe following interpretations of the word: any of the items in the list,all of the items in the list, and any combination of the items in thelist. All numerical values provided herein are intended to includesimilar values within a measurement error.

Moreover, conditional language used herein, such as, among others,“can,” “could,” “might,” “may,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states.

The teachings of the inventions provided herein can be applied to othersystems, not necessarily the systems described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments. The acts of the methods discussed hereincan be performed in any order as appropriate. Moreover, the acts of themethods discussed herein can be performed serially or in parallel, asappropriate.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms. Furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure. Accordingly,the scope of the present inventions is defined by reference to theclaims.

What is claimed is:
 1. An apparatus comprising: an electrical overstressprotection device; a detection circuit electrically coupled to theelectrical overstress protection device, the detection circuitconfigured to detect an occurrence of an electrical overstress event;and a memory configured to store information indicative of theelectrical overstress event detected by the detection circuit.
 2. Theapparatus of claim 1, further comprising a resistive element disposedbetween the electrical overstress protection device and a low referencevoltage, the resistive element also disposed between an input of thedetection circuit and the low reference voltage reference, wherein theelectrical overstress protection device is configured as an electricaloverstress sense device.
 3. The apparatus of claim 2, further comprisinga second electrical overstress protection device in parallel with aseries combination of the electrical overstress device and the resistiveelement.
 4. The apparatus of claim 3, wherein the electrical overstressprotection device is a scaled down replica of the second electricaloverstress protection device.
 5. The apparatus of claim 1, wherein theelectrical overstress event is an electrostatic discharge event and theelectrical overstress protection device is an electrostatic dischargeprotection device.
 6. The apparatus of claim 1, further comprising aninput pin, an internal circuit, and an electrical overstress isolationdevice disposed between the input pin and the internal circuit, whereinthe electrical overstress protection device is electrically connected tothe input pin.
 7. The apparatus of claim 1, wherein the detectioncircuit is further configured to detect an intensity of the electricaloverstress event and the information indicative of the electricaloverstress event comprises an indication of the intensity of theelectrical overstress event.
 8. The apparatus of claim 1, wherein thedetection circuit comprises at least one comparator configured tocompare a voltage associated with the electrical overstress event with areference voltage.
 9. The apparatus of claim 1, wherein the informationindicative of the electrical overstress event comprises an indication ofa number of electrical overstress events detected by the detectioncircuit.
 10. The apparatus of claim 1, further comprising a reportingcircuit configured to provide the information indicative of theelectrical overstress event to external circuitry.
 11. The apparatus ofclaim 1, wherein the memory comprises non-volatile memory elements. 12.The apparatus of claim 1, wherein the detection circuit comprises aplurality of fuse elements each configured to blow at different voltagelevels, and wherein the memory comprises the plurality of fuse elements.13. The apparatus of claim 1, wherein the electrical overstress device,the detection circuit, and the memory are included within a singlepackage.
 14. The apparatus of claim 1, further comprising a storageelement configured to store energy associated with the electricaloverstress event.
 15. An apparatus comprising: an electrical overstressprotection device; a detection circuit electrically connected to theelectrical overstress protection device, the detection circuitconfigured to detect an occurrence of an electrical overstress event;and a reporting circuit in communication with the detection circuit, thereporting circuit configured to provide information indicative of theelectrical overstress event detected by the detection circuit.
 16. Theapparatus of claim 15, wherein the electrical overstress protectiondevice and the detection circuit are embodied on a single die, andwherein the information indicative of the electrical overstress event isindicative of functional safety of the single die.
 17. The apparatus ofclaim 15, wherein the electrical overstress protection device and thedetection circuit are embodied on a single die, and wherein theinformation indicative of the electrical overstress event is indicativeof functional safety of an electronic system that includes the singledie and other electronic components.
 18. The apparatus of claim 15,wherein the electrical overstress protection device and the detectioncircuit are embodied on a single die, and wherein circuitry protected bythe electrical overstress protection device is external to the singledie.
 19. The apparatus of claim 15, further comprising: a pin, whereinthe electrical overstress protection device is disposed between the pinand the detection circuit; a resistive element in series with theelectrical overstress protection device, wherein the detection circuitis electrically connected to a node between the resistive element andthe electrical overstress protection device, and wherein the electricaloverstress protection device is configured as an electrical overstresssense device; and a second electrical overstress protection device inparallel with a series combination of the resistive element and theelectrical overstress protection device.
 20. The apparatus of claim 15,further comprising a storage element configured to store energyassociated with the electrical overstress event.
 21. The apparatus ofclaim 15, wherein the reporting circuit is configured to wirelesslytransmit the information indicative of the electrical overstress event.22. An electronically-implemented method of recording informationassociated with an electrical overstress event, the method comprising:detecting, using detection circuitry electrically connected to anelectrical overstress protection device, an occurrence of an electricaloverstress event; and recording information associated with theoccurrence of the electrical overstress event to a memory.
 23. Themethod of claim 22, further comprising reporting the informationassociated with the occurrence of the electrical overstress eventexternal to a die on which the detection circuit is embodied.
 24. Themethod of claim 22, wherein the information associated with theoccurrence of the electrical overstress event comprises informationindicative of an intensity of the electrical overstress event.